A 5‐year study of the prevalence and genetic diversity of human caliciviruses associated with sporadic cases of acute gastroenteritis in young children admitted to hospital in Melbourne, Australia (1998–2002)

Abstract The prevalence and genetic diversity of human caliciviruses causing sporadic cases of acute gastroenteritis in young children hospitalized in a large pediatric hospital in Melbourne, Australia over 5 years (incorporating January 1998–December 2002) was studied by reverse transcription and sequence analysis of part of the polymerase gene. The overall prevalence of calicivirus infection in children aged <5 years during the 5 year study was 9.2% (113/1,233), with 95% of the strains belonging to the Norovirus genera. Strains of the norovirus G11‐4 cluster were the most common type identified in 4 of the 5 years studied (1998, 1999, 2001, and 2002), with strains of norovirus cluster G11‐5 the most common type during 2000. Additional norovirus genetic clusters GI‐3, GII‐1, GII‐2, GII‐3, GII‐6, and GII‐7, were also identified, but comprised only 17/94 of norovirus genogroup II strains. Five sapovirus strains were also identified. These results highlight the divergence of norovirus strains identified in a pediatric population. J. Med. Virol. 77:96–101, 2005. © 2005 Wiley‐Liss, Inc.